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Rapid TB test increased same-day treatment initiation
A rapid test for tuberculosis improved the time to diagnosis and treatment in a randomized trial, according to study results published in The Lancet.
Use of the Xpert MTB/RIF test (Cepheid) was found to increase the number of people starting treatment after testing positive on day 1 by 50% compared with smear microscopy.
“Despite already being rolled out in many countries, our study is the first to look at the feasibility of the Xpert test in a real-life clinical setting in southern Africa,” Keertan Dheda, PhD, of the department of medicine at the University of Cape Town in South Africa, said in a press release. “Although earlier diagnosis by the Xpert test did not reduce overall severity of TB-related illness, and moreover did not reduce the overall number of TB cases treated over the course of the study, it has substantial benefits over smear microscopy, including improved rates of same-day diagnosis and reducing treatment drop-out.”
Dheda and colleagues evaluated the test from April 21, 2011, to March 30, 2012. They randomly assigned 758 patients (182 were culture-positive) to smear microscopy and 744 (185 were culture-positive) to Xpert MTB/RIF. Point-of-care MTB/RIF test had a higher sensitivity compared with microscopy (83% vs. 50%), but they had similar specificity (95% vs. 96%). The point-of-care test had similar sensitivity to laboratory-based MTB/RIF (83% vs. 83%), but had higher specificity (95% vs. 92%).
More patients in the MTB/RIF group had a same-day diagnosis (24% vs. 13%) and same-day treatment initiation (23% vs. 15%) compared with microscopy. There also was a lower dropout rate (15% vs. 8%). However, there was no difference in severity of TB-illness between the groups among culture-positive patients at baseline, 2 months and 6 months after treatment.
“Whilst Xpert may not be the ideal point of care TB test in particularly poorly resourced settings, in countries like South Africa where clinic infrastructure is relatively good, rates of drug-resistant TB are high and patient drop-out is a significant problem, within clinic placement of Xpert in TB hotspots might be appropriate and enable earlier diagnosis of drug-resistant TB, thus likely reducing community-based transmission,” Dheda said. “Nevertheless, prevention of TB and adherence to TB treatment is critical and remains a major priority.”
Disclosure: The researchers report no relevant financial disclosures.